Spatial variability of drought impacts

Hydrological and historical documentary data were analysed alongside the scPDSI time series for two severe droughts identified here, including; the well-documented drought of the mid 1990s (1995-97), discussed at length by Marsh (1996) and Walker and Smithers (1998), and the lesser documented event of 1864-1871, to briefly investigate the spatial variability of impacts of severe/extreme historical droughts, and corroborate severe droughts identified here using the scPDSI method.

1989-2010 (mid-1990s)

Extreme meteorological drought conditions during the mid-1990s were identified at all seven sites by the scPDSI, and were part of much longer-duration events at some sites (1989-2010, Carlisle, Appleby, Barnacre, and Manchester Figure 6.3, Tables 6.3 and 6.4). Drought conditions during the mid-1990s ranked amongst the top ten most severe on

Site Carlisle Geltsdale Appleby Thirlmere Barnacre Longdendale Manchester

Carlisle 0.33 0.84 0.25 0.74 0.38 0.53 Geltsdale 0.33 0.36 0.22 0.34 0.66 0.50 Appleby 0.84 0.36 0.24 0.66 0.41 0.59 Thirlmere 0.25 0.22 0.24 0.14 0.11 0.30 Barnacre 0.74 0.33 0.66 0.14 0.56 0.55 Longdendale 0.38 0.66 0.41 0.11 0.56 0.60 Manchester 0.53 0.50 0.59 0.30 0.55 0.60

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record and are one of the benchmark historical droughts used for water resources management in northwest England (Revised draft drought plan, United Utilities Plc. 2014). Monthly river flows and groundwater levels from across northwest England show sustained deviations from the long-term average during 1995-97 and the lowest flows and levels on record during 1989-2008 (end 2010 at Barnacre, Figure 6.4); indicating that when meteorological drought conditions peaked in severity during the mid-1990s there were corresponding widespread hydrological impacts.

The overall pattern of low flows is coherent for the River Eden (chosen to represent hydrological impacts of drought at Carlisle, Geltsdale and Appleby), with similar coherence between the flows in the rivers Brock, Goyt and Bollin (representative of Barnacre, Longdendale and Manchester), where low flows were more sustained. This distinction in hydrological impacts is reflective of the different catchment types, with the north of the region dominated by more upland, flashy and responsive catchments and the south by more lowland, slower responding catchments (though the headwaters of the Bollin in the Peak District may exhibit a more flashy nature). The groundwater levels display the inverse of this relationship, with a less responsive sandstone aquifer in the north of the region and a more responsive limestone aquifer in the south. Groundwater levels during 1995-97 also show sustained deviations from long-term average (Figure 6.4). Reservoir levels for the series of reservoirs at Longdendale demonstrate a consistent drop in water level during summer-autumn 1995, (Figure 6.5). Rapid depletion of reservoir stocks were observed across the region, peaking in Autumn 1995, with Haweswater reservoir decreasing to 11% of capacity (Walker and Smithers 1998). Reservoir levels at Castle Carrock (near Geltsdale) also rapidly declined during 1995; although slightly earlier, in the spring.

Page | 127 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 Fl o w m 3s -1 0 50 100 150 200 250

Date vs LTA flow Date vs Rflow cumecs

Eden at Sheepmount mean monthly flow Long term mean monthly flow

1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 Fl o w m 3s -1 0 2 4 6 Date 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 Gro u n d w a te r le v e l (m A OD ) 129 130 131 132 133 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 Fl o w m 3s -1 0 20 40 60 80 100 120 140 160 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 Fl o w m 3s -1 0 20 40 60 80

Long term mean monthly flow Eden at Temple Sowerby mean monthly flow

Long term mean monthly groundwater level Skirthwith mean monthly groundwater level

Long term mean monthly flow Eden at Warwick Bridge mean monthly flow

Long term mean monthly flow St Johns Beck mean monthly flow

Page | 128 Figure 6.4: Monthly river flows and groundwater levels across northwest England during 1989-2008 (end 2010 for the river Brock near Barnacre). Periods below the long-term average are shaded in red

1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 Fl o w m 3s -1 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

Brock at U/S A6 mean monthly flow Long term mean monthly flow

1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 Fl o w m 3s -1 0 2 4 6 8 10 12 14 16 18

Long term mean monthly flow Goyt at Marple Bridge mean monthly flow

Date 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 G ro un dw at er le v el ( m A O D ) 250 260 270 280 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 Fl o w m 3s -1 0 1 2 3 4 5

Long term mean monthly groundwater level Hucklow South mean monthly groundwater level

Long term mean monthly flow Bollin at Wimslow mean monthly flow

Page | 129 Figure 6.5: Reservoir levels for a) the Longdendale reservoir system during 1995-1997 (meters below top water level) and b) Castle Carrock reservoir for 1995. Note the different y-axis M B TW L (m ) 0 5 10 15 Date 1994 1995 1996 1997 % o f n e t sto ra g e 0 20 40 60 80 100 Castle Carrock

a

b

Woodhead Torside Rhodeswood Valehouse Bottoms

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1864-1871

Hydrological time series are typically much shorter in length than meteorological series in the UK, with the majority of records started during the 1960s and very few available for the nineteenth century (Bayliss and Reed 2001). Therefore, historical documentary data sources pre-dating the onset of hydrological recording must be used as evidence of the impact of droughts occurring prior to the mid-twentieth century and to corroborate the scPDSI series. An approach applied by Cole and Marsh (2006) and Marsh et al. (2007) in their identification and classification of major droughts in England and Wales during 1800- 2006.

For varying periods during 1864-1871 severe drought conditions were identified at Carlisle, Appleby, and Longdendale, and were approaching severe status at Manchester (scPDSI - 2.9, Table 6.2). Historical documentary information (relating to northwest England) indicates that significant rainfall deficiencies occurred across the region during 1864-1871 (Table 6.6), and widespread environmental (hydrological, groundwater) and socio- economic (agricultural, social, water resource) impacts were experienced when drought conditions reached severe status during 1868-1871 (Figure 6.3, Table 6.6). In an identification of major droughts in England and Wales for 1800-2006, Cole and Marsh (2006) show that this drought period was of national importance, with impacts of drought conditions first experienced in western England, spreading to all regions towards the end of the drought period. Further evidence of the impacts of the 1864-1871 drought experienced in northwest England are presented by Cole and Marsh 2006 (Appendix 2).

Page | 131 Table 6.6: Documentary records of drought impacts during 1864-1871

Date Quotation Source

Meteorological

July 1864 "There was a little rain during the first three days; otherwise, at the majority of English stations, it was a month of continued drought. At most stations, the fall was below the average: at many of the English ones, not a quarter of the average, and at some far less even than that."

Symons, British Rainfall, 1864

February 1865 "With the exception of the northwestern counties of England, most parts appear to have had about, or above, their average supply of water, although much of it fell as snow."

Symons, British Rainfall, 1865

1867 "In those parts of Cumberland which are distant from the mountains, the year 1867 has been one of remarkable dryness…"

I. Fletcher, Symons British Rainfall, 1867 November 1867 "A remarkably fine, dry month. No station had its average fall, and

many had not one-third of the usual amount; barometer very high throughout."

Symons, British Rainfall 1867

1868 Downham Hall, Clitheroe "This year, in spite of the drought in summer, is 3in. Above the average for the last 14 years."

Symons, British Rainfall 1868 1868 Northallerton "The past summer was unusually hot and dry…" Symons, British

Rainfall 1868 August 1869 "A third consecutive dry month, accompanied by great heat. In

every part of the British Isles the fall was below the average."

Symons, British Rainfall 1869 1870 Observer from Allithwaite, northwestern counties "The least rain I

have ever had to register in one year."

Symons, British Rainfall 1870 June 1870 "At the majority of stations this was the fourth consecutive month

of deficient rainfall. A few thunder-showers passed about, but from their brevity and the heated condition of the ground, they produced but a very trifling effect on the browned and burnt surface of what should have been verdant lawns, but actually were little better than roadside paths."

Symons, British Rainfall 1870

August 1870 "The sixth consecutive month of which the rainfall of these islands were below the average…in the Lake District this usually wet month was remarkably fine."

Symons, British Rainfall 1870

September 1870 " The seventh and last of the dry months in England." Symons, British Rainfall 1870 October 1870 "…In the north and north-west…the fall was below the average." Symons, British

Rainfall 1870 December 1870 "..and a comparatively dry one [month] in Ireland, Wales and the

west of England."

Symons, British Rainfall 1870 1871 Observer from Bolton-Le-Moors, northwestern counties "The fall in

1871 (40.93) was 2.54 in. less than the fall in 1870, and 6.20 less than the mean of the previous 40 years."

Symons, British Rainfall 1871

May 1871 "A very dry month, the rainfall scarcely half the average, and at stations in the west of England…scarcely one quarter."

Symons, British Rainfall 1871

Agricultural

1868 "The drought and harvest in Westmoorland…the harvest progresses with vigour.The yield of wheat is unprecedendetly abundant…while the oaten and barley crops are just the reverse, the ear being small and chaffy, and the straw short and

thin…Turnips suffer greatly."

Symons, British Rainfall 1868

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Hydrological

1868 The drought and harvest in Westmoorland "…all the minor streams being quite dried up and the very largest of the rivers are reduced to the merest driblets."

Symons, British Rainfall 1868

August 1868 Quoting Mr Marshall's Abstract of Meteorological Observations in Kendal "Beginning with the advent of May to the 11th of August, the [drought] duration was 102 days, there being but slight showers on 36 days, and never half an inch was measured on any of these days. This is the longest period of drought that I have registered in 47 years, the nearest approach to it being 1852, when there was a greater amount of dry weather than even in the well- remembered season of 1826."

CBHE

October 1868 23rd October 1864 The Sunday Times "…the river [Ribble] was much below its usual depth, owing to the recent protracted drought."

The Sunday Times, 1864

October 1868 "At Preston the reservoir became practically dry at the end of August, and costly pumping works were hastily established, which were required for 58 days."

CBHE

July 1870 1870 July/August Seathwaite: The lowest summer two months rainfall over the 1845-94 period: 4.43 in.

CBHE

September 1870 "...in the Kendal district the [rainfall] drought during the three months July to September, 1913, was equalled in these months only in 1870 during the last 108 years"

CBHE

Groundwater

1868 …"Even the permanent wells are giving indications of exhaustion." Symons, British Rainfall 1868

socio-economic

April 1868 14th April 1868 The Manchester Guardian writing about the Liverpool Cattle Market "… the demand, owing to the great heat of the weather and long-continued drought , was very dull for cattle. Sheep and Lambs at much lower prices."

The Manchester Guardian

1868 The drought and harvest in Westmoorland "…all the minor streams being quite dried up and the very largest of the rivers are reduced to the merest driblet, of course rendering the prosecution of factory and mill work by means of water power quite impossible."

Symons, British Rainfall 1868

1868 "There is very little water for domestic purposes, and in the towm of Kendal the inhabitants have received notice, in fact, they are now under notice, to preserve their consumption 'as much as possible'..."

Symons, British Rainfall 1868

Water resource

July 1868 "…Towards the end of the month several towns in Lancashire were placed on short water-supply."

Symons, British Rainfall 1868 August 1868 3rd August 1868 The Times "Windermere Lake is, at this date.... 7 ft.

2 in. lower than the highest high-water mark, and that

notwithstanding ... the advantage of a considerable body of water let out of Stickle Tarn to supply the [gun]powder works at Elterwater. The long drought ... unprecedented during the past 46 years ... may be dated from the 1st of May."

The Times and Symons British Rainfall, 1868

1868 " At preston the reservoir became practically dry at the end of August, and costly pumping works were established, which were required for 58 days."

Chronology of British Hydrological Events, University of Dundee

September 1868 15th September 1868 The Manchester Guardian " The long continuing drought, and the consequent diminished supply of water to the inhabitants of Manchester…The Kidfield springs…are lower now than they were before the rains in August. Upon the moors the bops are all dry, and great fissures and cracks in the earth serve to suggest how much rain the land will swallow before the springs are in the slightest degree affected."

The Manchester Guardian

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In document Reconstructing long-term records of UK drought and analysis of variability: 1697-2013 (Page 133-141)